Method for the production of an agent from larvae in flies for treating wounds and agent produced according to said method

ABSTRACT

The treatment of wounds by means of larvae from flies is improved by virtue of the fact that the larvae are contaminated with bacteriophages.

CROSS REFERENCE TO RELATED APPLICATION

This application is a national stage of PCT/EP2004/009244 filed Aug. 18,2004 and based upon DE 103 42 104.1 filed Sep. 10, 2003 under theInternational Convention.

BACKGROUND OF THE INVENTION

1. Field of the invention

The invention concerns a process for the production of a means fortreating a wound.

2. Description of Related Art

It is known that the larvae of flies, in particular the larvae of fliesof genus Lucilia, have an effect of promoting healing of wounds. Thesecretion secreted by the living larvae stimulates tissue proliferation,liquefies necrotic tissue and scabs by proteolysis, and has anantiseptic effect against certain bacteria types, for exampleStreptococcus and Staphylococcus. The use of living larvae for treatmentof wounds is described in, for example, DE 19901134A1.

Further, to simplify the production and application of larvae in thatthe eggs of the flies, it is known from DE 19925996A1 to bring thelarvae in an early stage of development into environmental conditionswhich interrupt the development cycle. The breeding or rearing of larvaecan in this manner be carried out in a sterile manner in a commercialundertaking. The eggs or the larvae are brought, at an early developmentstage, prior to onset of their active phase, into thedevelopment-inhibiting environment and are packaged in thisdevelopment-inhibiting environment. The eggs, or as the case may be, thelarvae, can be transported in this condition from one location toanother and be stored by the manufacturer or the end user in thiscondition for prolonged period of time. Prior to the therapeuticapplication, the eggs or, as the case may be, the larvae, are thenbrought into an environment in which the development cycle can resume,so that the larvae enter into their active phase, in which they can beapplied to the wound.

SUMMARY OF THE INVENTION

The invention is concerned with the task of improving the effectivenessof wound treatment with larvae.

This task is inventively solved by a process for producing a means forwound treatment.

Advantageous embodiments of the invention are set forth in the dependentsubclaims.

The essential concept of the invention is comprised therein, that thelarvae therapy is to be enhanced by an application of bacteriophages.

Bacteriophages, also referred to as phages, are viruses, of which thehost cells are bacteria. The phages penetrate into the bacteria andreplicate in the inside of the bacteria cells. Temperate phages carryout a lysogenic condition in the bacteria, in which the bacteria cansurvive. Virulent or lytic phages multiply very rapidly in the bacteriaand disrupt this, so that they are released in the subsequent lysis. Itis known to employ living phages for treatment of bacterial infections.Therein it is necessary to employ phages with the highest possiblevirulence against the target bacteria. These phages are particularlysuited for treatment of infections, since in comparison to frequentlyemployed broad-spectrum antibiotics they have hardly any side effectsdue to their high specificity. In particular, the phages can also killgerms that exhibit a multi-resistance against antibiotics. Therein it isadvantageous that the phages multiply very rapidly exponentially untiltheir nutrient reserve is exhausted, that is, until bacteria no longerare present. In the manner typical for virus they can now transitioninto the lifeless rest condition (virions), in which they remain until arenewed contact with a specific target bacteria again revives theirreproduction.

DETAILED DESCRIPTION OF THE INVENTION

The invention is based upon a synergistic interaction between the larvaeand the bacteriophages.

The larvae are mobile and can, in accordance with the invention, serveas transport means and carriers for the phages, thereby bringing theimmobile phages into the areas of the wound to be treated. Therein it isimportant that the larvae become active in the wound areas in whichnecrotized tissue is located and thus where an increased danger ofinfection exists. By means of the larvae thus a local targetedapplication of phages is made possible. Therein the contamination of thelarvae with the phages supplementally has the advantage, that the phagesare not washed away by the wound discharge or emissions, which thusimproves their effectiveness.

The phages can not remove or penetrate bandages or other barriers, whichsurround necrotic and infected tissue. There is thus the advantage herein accordance with the invention that the larvae with their sharp teethand horns and their necrolytic secretion can attack and penetrate suchwound coverings and barriers, so that the phages can become effectivewith high efficiency.

The phages require for their replication and effectiveness anenvironmental temperature maintained as precisely as possible, forexample at 37° C. and preferably a alkali environment. Here also thereis in accordance with the invention an advantageous interaction, inwhich the larvae produce an alkali wound environment with theirsecretion and by their metabolism cause a temperature rise at the woundsurface. Thereby the larvae produce optimal environment conditions forthe replication of the phages. The antiseptic effect of the larvalsecretion is limited to specific causative organisms or pathogens, inparticular to Streptococci and Staphylococci. In the course of prolongedlarval treatment, thus, by the alkali wound environment, advantageouslya super-infection of the wound with grahm-negative pathogens such asPseudomona and Proteus can be fostered. These problems of a pure larvaltherapy can be avoided, or at least strongly be minimized, by thecontamination of the larvae with selected pathogens. The antiseptic andantibiotic spectrum of action of the larval secretion is stronglyadvanced by the supplemental application of the phages.

In order to achieve an optimal prophylaxis and therapy of woundinfections, it is useful to make available a broad spectrum of specificphages from which to select, which target the various bacteria to becombated. Thereby it is also possible, to reduce the likelihood ofdevelopment of resistance to the phages.

For a targeted application of the phages, it is important to breed theflies in a sterile-as-possible environment, so that the eggs of theflies are preferably already obtained in a substantially germ-freeenvironment. The breeding of the larvae from the egg stage occurs understerile conditions. The contamination with the selected strains ofphages could occur already in the egg stage or also in the subsequentlarval stage. Since the phages remain in their lifeless virion restcondition so long as no target bacteria are present, the rearing of thelarvae is possible even in the case of an early contamination, forexample in the egg stage.

Preferably at a very early development stage in the production processthe eggs of the flies or the larvae are introduced into an environmentalcondition in which the development cycle is stopped. Such anenvironmental condition could be for example a reduced temperature, avacuum or an inert atmosphere, or as a consequence of removal ofmoisture. In this condition the eggs or larvae contaminated with thebacteriophages can be preserved in the manufacturing facility and betransported to the end user. After reaching the end user a furtherstorage is also possible, until the larvae are applied for woundtreatment. Prior to the planned application the eggs or, as the case maybe, the larvae in the early development stage, are brought out of thedevelopment inhibiting environmental condition into an environment inwhich the development cycle of the larvae can proceed, so that thelarvae can rapidly develop into their active phase, in which conditionthey are applied to the wound. In the storage and the transport thephages can supplementally also ensure the maintenance of the germ-freestate of the larval product, which is necessary for a therapeuticapplication.

The synergistic effect of the larval secretion and the bacteriophagescan also be taken advantage of in the manner, that the larval secretionand the phages are applied jointly upon a wound inlay or padding orintermediate layer, which is then applied upon the wound surface. Thelarval secretion can be secreted from the living larvae onto the woundinsert, can be obtained by rinsing off of the larvae, or can beextracted from the larvae. The necrotic effect of the larval secretion,the decomposition of barriers which block the effect of the phages, andthe alkali influence of the wound environment also provides supporthere.

1. A process for producing a means for wound treatment, in which larvaeto be applied to the wound to be treated are raised from the eggs offlies, wherein the larvae are contaminated with bacteriophages in themanner that the larvae to be applied become the carriers of thebacteriophages.
 2. A process according to claim 1, wherein at least therearing of the larvae from the egg stage is carried out under sterile orgerm suppressing environmental conditions.
 3. A process according toclaim 1 or 2, wherein the contamination with the bacteriophages iscarried out in the egg stage.
 4. A process according to claim 1, whereinthe contamination with the bacteriophages is carried out in thedevelopment stage of the larvae, before the larvae become active forwound treatment.
 5. A process according to claim 1, wherein the eggs orthe larvae are contaminated with bacteriophages in the early larvalstage, and that the eggs or, as the case may be, the larvae in theirearly development stage are brought into an environmental condition forstorage and/or transport in which the development cycle is arrested. 6.A composition for wound treatment, which contains living larvae offlies, which larvae are to be applied to the wound to be treated,wherein the larvae are contaminated with bacteriophages.
 7. Acomposition according to claim 6, wherein the larvae prior tocontamination with the bacteriophages are germ-free.
 8. A compositionaccording to claim 6, wherein the larvae are contaminated with thebacteriophages in the egg stage or, as the case may be, an early larvalstage, and enclosed in an environment in which their development cycleis inhibited.
 9. A process for wound treatment with larvae of flies, inwhich living larvae are applied to the wound, wherein the larvae arecontaminated with bacteriophages and carry these bacteriophages into thewound.
 10. A process according to claim 9, wherein the larvae produce inthe wound an alkali wound environment and an elevated temperaturefavorable to the development of the bacteriophages.
 11. A processaccording to claim 9, wherein the larvae break down wound coverings andbacteria-shielding protective layers by at least one of their secretionand their mouth hooks or teeth.
 12. A process for producing a means forwound treatment, in which the secretion of the larvae of flies isapplied upon a wound covering, wherein bacteriophages are also appliedonto the wound covering.
 13. An article for wound treatment, with awound covering soaked with the secretion of larvae, wherein the woundcovering further contains bacteriophages.
 14. A process for woundtreatment with the secretion of the larvae of flies, whereinbacteriophages are mixed into the secretion.
 15. A process according toclaim 9, wherein the larvae of flies are of the genus Lucilia.